docs: def to_json(self):
          """
          Prepare data for the initial state of the admin-on-rest
          """
          endpoints = []
          for endpoint in self.endpoints:
              list_fields = endpoint.fields
              resource_type = endpoint.Meta.resource_type
              table = endpoint.Meta.table
  
              data = endpoint.to_dict()
              data['fields'] = resource_type.get_type_of_fields(
                  list_fields,
                  table,
              )
              endpoints.append(data)
  
          data = {
              'title': self.title,
              'endpoints': sorted(endpoints, key=lambda x: x['name']),
          }
  
          return json.dumps(data)